1、Designation: C 1394 03Standard Guide forIn-Situ Structural Silicone Glazing Evaluation1This standard is issued under the fixed designation C 1394; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number
2、in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.INTRODUCTIONSSG is popular because of its unique method of retaining glass or other panels in smooth exteriorwalls, interrupted only by narrow sealant jo
3、ints. The first four-sided SSG in commercial constructionis on the former corporate headquarters building of SHG Incorporated (formerly known as Smith,Hinchman unknown structuralsealant durability; and the level of understanding of the principles of SSG by glazers. This guideaddresses these concerns
4、 by providing suggestions for in situ evaluations of completed installations ofany age.1. Scope1.1 It is recommended to periodically evaluate the existingcondition of structural sealant glazing (hereinafter called SSG)installations in situ to detect problems before they becomesevere or pervasive. Ev
5、aluation of existing SSG installationsare required by certain building codes and local ordinances.This guide provides a program to evaluate the existing condi-tions, lists typical conditions, which might be found, andsuggests times when such evaluations are appropriate. Thecommittee with jurisdictio
6、n over this standard is not aware ofany comparable standards published by any other organiza-tions.2. Referenced Documents2.1 ASTM Standards:2C 717 Terminology for Building Seals and SealantsC 1392 Guide for Evaluating Failure of Structural SealantGlazingC 1401 Guide for Structural Sealant GlazingE
7、122 Practice for Choice of Sample Size to Estimate aMeasure of Quality for a Lot or Process3. Terminology3.1 Definitions: The definitions of the following terms usedin this guide are found in Terminology C 717: structuralsealant; structural sealant glazing; two-sided structural sealantglazing; four-
8、sided structural sealant glazing; fluid migration.3.2 Definitions of Terms Specific to This Standard:3.2.1 qualified personone with a recognized degree orprofessional registration and extensive knowledge and experi-ence in the field of structural sealant glazing, and who iscapable of design, analysi
9、s, evaluation, and specifications inthe subject.4. Significance and Use4.1 Guidelines are provided for the procedures to evaluateexisting SSG installations, including two- and four-sidedinstallations. Due to the unlimited range of materials that maybe used in a particular building, the information c
10、ontained inthis guide is general in nature. For a discussion of new SSGinstallations, refer to Guide C 1401.4.2 Typical conditions are listed that might be discoveredduring, or suggest the need for, such evaluations. Guidelinesare also suggested for times to perform evaluations. Theseguidelines are
11、also necessarily general. Professional judgmentof a qualified person should be used in determining theappropriate time to perform an evaluation on a particularbuilding.1This guide is under the jurisdiction of ASTM Committee C24 on Building Sealsand Sealants and is the direct responsibility of Subcom
12、mittee C24.10 on Specifi-cations, Guides, and Practices.Current edition approved Dec. 1, 2003. Published January 2004. Originallyapproved in 1998. Last previous edition approved in 1998 as C 139498.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service
13、at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.3 This guide should not be the only reference
14、consultedwhen determining the scope of a proposed evaluation. Forexample, the local building code and the manufacturersproduct literature for the actual materials used (if known)should also be considered.4.4 This document is not a substitute for experience andjudgment in assessing the condition of t
15、he specialized types ofconstruction discussed.5. Reasons to Perform an Evaluation5.1 There are numerous reasons that a building owner ormanager (hereinafter “owner”) may choose to evaluate an SSGsystem, whether discretionary or to comply with an ordinance.The recommended evaluation levels, as discus
16、sed in Section 7,are referenced for each situation. The findings from one levelof investigation may trigger the need for a more in-depthinvestigation. At a minimum, it is recommended that anexisting SSG installation be evaluated when triggered by anyof the following events:5.1.1 After a natural disa
17、ster, such as an earthquake or majorwind storm, or a man-made disaster such as a bomb blast,Level 2;5.1.2 After a recall or published concern over a specificproduct or system, Level 1;5.1.3 Upon a change of property ownership, Level 1;5.1.4 Before repeating a new design, Level 1;5.1.5 As dictated by
18、 government regulations, Level 1 or 2;or5.1.6 When distress is discovered (see Section 8), Level 2,or, if prevalent distress is found, Level 3.5.2 In addition to event-triggered evaluations, it is recom-mended that proactive owners also perform periodic evalua-tions at the following intervals: (Note
19、 that some of theseperiods may overlap. If distress is found during any evaluation,then more frequent and more in-depth evaluations should beconsidered.)5.2.1 When convenient, such as in conjunction with occa-sional glass replacement, or when access is available, Level 1;5.2.2 Immediately after inst
20、allation of a new system, Level2;5.2.3 Just before expiration of the warranty period, Level 2;5.2.4 Between 1 and 2 years after substantial completion,Level 1;5.2.5 After 5 years, Level 1;5.2.6 After 10 years, Level 2;5.2.7 After 15 years, Level 1 (if Level 2 was performed asrecommended after 10 yea
21、rs); and5.2.8 After 20 years, and each successive 10 years, Level 2.6. Symptoms of Problems With SSG6.1 Whether due to original construction mistakes or latentdefects, SSG installations sometimes exhibit distress. Thefollowing list summarizes conditions that may indicate poororiginal construction or
22、 a subsequent failure of the structuralsealant, and therefore require evaluation. This list may not beall-inconclusive.6.1.1 Glass breakage from an unknown causeThere arenumerous potential causes of spontaneous glass breakage; ifthe cause is unknown, then it should be investigated prior toglass repl
23、acement whether an SSG defect contributed to thefailure.6.1.2 Air or water infiltrationIf air or water migratesthrough or to the structural sealant joint, then it must also havelost its structural functionat least for part of its length.Symptoms of air or water leakage include:6.1.2.1 Visible accumu
24、lation of liquid water during orfollowing storms;6.1.2.2 Wet insulation;6.1.2.3 Organic growth;6.1.2.4 Water stains or salt deposits;6.1.2.5 Audible rattle or whistle;6.1.2.6 Discoloration of laminated glazing;6.1.2.7 Condensation or frost on glazing;6.1.2.8 Fogging of insulated glass units;6.1.2.9
25、Opacifier failure on spandrel glassMoisture is afactor in the failure of some opacifiers, and may indicate waterinfiltration; and6.1.2.10 Visible sealant failures Sealant failures may beobserved from inside or outside, depending on the design, andmay involve the weather-seal joint as well as the str
26、ucturaljoint. Visible manifestations of sealant failures include:6.1.2.10.1 Intermittent loss of adhesionNonadhered seal-ant may differ in iridescence or reflectivity compared toadhered sealant when viewed through the glass;6.1.2.10.2 Fluid migration or exudation The accumula-tion of a fluid residue
27、 on the sealant or glass may indicate achemical reaction between the sealant and an incompatibleadjacent material;6.1.2.10.3 Discoloration of the sealantA color changemay indicate a chemical reaction between the sealant and anincompatible adjacent material;6.1.2.10.4 Cohesive failureAlthough difficu
28、lt to observefrom inside or outside, cohesive failure could indicate over-stressing of the sealant;6.1.2.11 Disengaged or nonaligned lites, or displaced spac-ers or setting blocks, which may indicate glass displacement;and6.1.2.12 Poor dimensional control of a structural sealantjointWhen viewed from
29、 inside or outside, the structuralsealant should have uniform dimensions and full joints. Vary-ing dimensions may indicate poor original installation prac-tices, or improper/inadequate cure of the sealant.7. Procedures for Evaluating Existing Conditions7.1 The following evaluation procedures are rec
30、ommendedto be performed in determining the condition of an SSGinstallation. Depending on the reason for the evaluation and thetype of installation, only certain procedures may be necessary;for example, more scrutiny is warranted for high-rise, 4-sidedSSG than for low-rise, 2-sided SSG. The objective
31、 of theevaluation is to obtain a reasonable degree of confidence in theexisting system, since one hundred percent certainty is notpossible.C13940327.2 Different levels of expertise are needed to perform thevarious levels of evaluation, but in all cases a qualified personshould supervise the evaluati
32、on.7.3 Level 1Perform all of the following evaluation proce-dures:7.3.1 Review project documentation, including original de-sign drawings, shop drawings, mock-up testing report, andprevious evaluation reports. Review original SSG designcalculations, or if not available, perform calculations to deter
33、-mine stress on sealant from thermal and wind loading (and,where appropriate, seismic loading);7.3.2 Interview building management and maintenance per-sonnel and tenants regarding breakage history of lites and otherdistress. Map findings on elevation drawings, and assesswhether a pattern exists; and
34、7.3.3 Perform a cursory visual assessment from the interior,and from the exterior ground, roofs, and balconies.7.4 Level 2Perform the following, plus all of the proce-dures of Level 1 (unless a Level 1 evaluation has beenperformed previously and the documentation recommended tobe kept by the owner i
35、n 8.2 is available):7.4.1 Perform close-up visual evaluation from the interior;7.4.2 Observe weatherseal joints and structural joints fromthe exterior. Document distress, and assess whether a patternexists. Utilize high-powered optical tools to assist in observingfrom remote viewing areas, or from s
36、uspended scaffolding.Choose scaffold “drops” to represent the entire building,including different wind zones, elevations, exposures, details,and construction times; and7.4.3 Qualitatively measure the sealant adhesion by press-ing in with a thumb. Alternatively, semi-quantitative adhesionstrength dat
37、a can be obtained using a Chatalon spring loadindicator, or pulling cut tabs to failure and measuring theelongation.7.5 Level 3Perform all of the following procedures underthe field supervision of a qualified person, plus the proceduresof Levels 1 and 2 (except that Level 1 may be eliminated if itha
38、s been performed previously and the documentation recom-mended to be kept by the owner in 8.2 is available:7.5.1 Consider whether the existing conditions indicate thatevaluation of all lites is warranted. If not, develop a rationalapproach for evaluating a representative sample of the totallites. Th
39、ere is a trade-off between accuracy and the cost of thestudy. For quantitative tests and measurements, it is recom-mended that the number of specimens or tests be selected toensure achieving at least a 90 % confidence interval with amaximum 20 % margin of error. Different levels of study mayrequire
40、stricter parameters; and7.5.2 Perform in-situ load testing on selected lites, either byuniform load (air pressure) or point load (suction cups). Oneapplicable test method is described in Guide C 1392.8. Report and Record Keeping8.1 At the conclusion of the evaluation, a written reportshould be prepa
41、red presenting findings, conclusions, and, ifappropriate, recommendations for remedial action.8.2 It is very important that the evaluation data be main-tained by the building owner in a standardized format tofacilitate comparisons over time. It is recommended that allevaluation reports be kept in on
42、e notebook binder, along withother information pertinent to the SSG installation.8.3 The report should provide the following information:8.3.1 Building identification, background information, andreferences to original design and construction firms.8.3.2 Purpose of evaluation, and triggering event or
43、 reason.8.3.3 Evaluation procedures used, including referencing thespecified levels of evaluation in this guide.8.3.4 Availability and adequacy of original design andconstruction documentation, drawings, and calculations, espe-cially in relation to current code requirements or state-of-the-art SSG d
44、esign procedures.8.3.5 Distress and defects observed.8.3.6 Changes since last evaluation.8.3.7 Field testing results. Record findings and test locationson elevation drawings in an appendix.8.3.8 Expected reliability of extrapolating the findings fromlimited areas to the entire system.8.3.9 Recommend
45、ations for further evaluation or remedialaction.9. Keywords9.1 distress; durability; glazing; structural glazing; struc-trual sealant glazing; structural sealant joint; structural silicone;SSG; SSG design calculation; SSG design procedure; SSGevaluation; SSG installations;C1394033APPENDIX(Nonmandato
46、ry Information)X1. BIBLIOGRAPHYX1.1 For more information see the following:X1.1.1 Documents prepared by manufacturers and tradeassociations:X1.1.1.1 Structural Silicone Glazing, by Dow Corning Cor-poration.X1.1.1.2 Structural Silicone Glazing Guide, by GeneralElectric (GE Silicones) CompanyX1.1.1.3
47、Architectural Guidelines for Glazing Systems, byTremco CorporationX1.1.1.4 Curtain Wall Manual No. 13, Structural SealantGlazing Systems (CW-13), AAMA, Schaumburg, Illinois,1985.X1.1.2 Books:X1.1.2.1 Sealants in Construction, Jerome M. Klosowski,Marcel Dekker, Inc., 1989.X1.1.2.2 Construction Sealants and Adhesives, Julian R.Panek or through the ASTM website(www.astm.org).C1394034
